Core temperature [ Time Frame: End of each dietary period ] [ Designated as safety issue: No ]

secreted frizzle-related protein-4 [ Time Frame: end of each dietary period ] [ Designated as safety issue: No ]

heme-oxygenase [ Time Frame: end of each dietary period ] [ Designated as safety issue: No ]

Irisin [ Time Frame: end of each dietary period ] [ Designated as safety issue: No ]

fibroblast growth factor-21 [ Time Frame: end of each dietary period ] [ Designated as safety issue: No ]

chemerin [ Time Frame: end of each dietary period ] [ Designated as safety issue: No ]

trimethylamine N-oxide [ Time Frame: fasting and postprandial, end of each dietary period ] [ Designated as safety issue: No ]

alanine aminotransferase [ Time Frame: end of each dietary period ] [ Designated as safety issue: No ]

Uric acid [ Time Frame: end of each dietary period ] [ Designated as safety issue: No ]

insulin [ Time Frame: fasting and postprandial, end of each dietary period ] [ Designated as safety issue: No ]

ghrelin [ Time Frame: fasting and postprandial, end of each dietary period ] [ Designated as safety issue: No ]

gastric inhibitory peptide [ Time Frame: fasting and postprandial, end of each dietary period ] [ Designated as safety issue: No ]

GLP1 [ Time Frame: fasting and postprandial, end of each dietary period ] [ Designated as safety issue: No ]

PYY [ Time Frame: fasting and postprandial, end of each dietary period ] [ Designated as safety issue: No ]

Amylin [ Time Frame: fasting and postprandial, end of each dietary period ] [ Designated as safety issue: No ]

Leptin [ Time Frame: end of each dietary period ] [ Designated as safety issue: No ]

Original Secondary Outcome Measures ICMJE (submitted: April 14, 2006)

total energy expenditure using doubly labeled water methodology

thermic effect of food using indirect calorimetry

physical activity using accelerometry

serum lipids

plasminogen activator inhibitor-1

C-reactive protein

blood pressure

other hormones (in addition to thyroid-related hormones)

hunger/appetite

Current Other Outcome Measures ICMJE

Not Provided

Original Other Outcome Measures ICMJE

Not Provided

Descriptive Information

Brief Title ICMJE

Popular Diets Study

Official Title ICMJE

Popular Diets, Metabolism, and CVD Risk

Brief Summary

The aim of this study is to evaluate the effects of three dominant dietary patterns - conventional low-fat, low-glycemic index (GI) and very-low-carbohydrate - on energy metabolism and heart disease risk factors following weight loss in obese young adults in a feeding study

Detailed Description

For most of the last half century, reduction in fat intake has been the primary nutritional approach for the prevention and treatment of obesity and cardiovascular disease (CVD). Over the last few years, very low carbohydrate (Atkins-type) diets have achieved great popularity, with publication of several studies suggesting greater weight loss and improvements in CVD risk factors over 3 to 6 months. Recently, a third dietary approach focused on glycemic index (GI) has generated interest. However, few studies have compared the effects of these diets on body weight regulation and risk for CVD. The primary hypotheses of this study are that any diet that lowers the postprandial rise in blood glucose (very-low-carbohydrate or low-GI) will have beneficial effects on the physiological adaptations to weight loss and on some CVD risk factors. However, other CVD risk factors will be adversely affected by a very-low-carbohydrate vs. a low-GI diet. Preliminary data provide strong support for these hypotheses, by showing that resting energy expenditure declines less and CVD risk factors improve more with weight loss on a low-glycemic load diet compared to a conventional low-fat diet. This application proposes a cross-over feeding design to study the effects of three diets following 12.5% weight loss in obese young adult subjects (n = 24, age 18 to 40 years). The diets are: 1) conventional low-fat, with 60% carb, 20% fat, 20% protein; 2) low-GI with 40% carb, 40% fat, 20% protein; and 3) very-low-carbohydrate with 10% carb, 60% fat, 30% protein. The primary outcome is resting energy expenditure (indirect calorimetry). Secondary outcomes include total energy expenditure (doubly labeled water), thermic effect of food (indirect calorimetry), physical activity (accelerometry), insulin resistance and B-cell function (frequently-sampled OGTT), blood lipids, blood pressure and measures of systemic inflammation and coagulopathy. This study should have major public health implications to the millions of Americans currently following diets to decrease body weight and risk for heart disease.